Wenger, EmanuelKarnaukhov, Victor N.Haidinger, Alois2015-11-112015-11-1119991017-4656https://doi.org/10.2312/egs.19991061The comparison of watermarks in old paper is the major technique for dating undated medieval manuscripts. The extraction of watermarks as contours is the crucial task in digitalization and building a watermark database. In this paper the method of object delineation by active curves (snakes) is modified and applied to the contour tracing and skeletonization of watermarks.